Follow the key events of the Soyuz rocket’s ascent into orbit from the Guiana Space Center with the SES 15 communications satellite. A listing of exact times for the flight’s major events is posted below.
Data source: Arianespace
T-0:00:03: Engines at Full Thrust
The five main engines of the Soyuz rocket’s core stage and four strap-on boosters are at full thrust.
Producing more than 900,000 pounds of thrust, the Soyuz ST-A (Soyuz 2-1a) rocket soars into the sky from the Guiana Space Center.
T+0:01:58: Jettison Boosters
The Soyuz rocket’s four strap-on boosters, each powered by an RD-107A engine, are jettisoned after consuming their propellant.
T+0:03:39: Jettison Fairing
The ST-type payload fairing is released from the Soyuz rocket when it reaches the edge of the upper atmosphere. The 13.5-foot-diameter fairing protects the payload during the launch countdown and the flight through the dense lower atmosphere.
T+0:04:47: Core Stage Separation
Having burned its propellant, the core stage of the Soyuz rocket, also known as the second stage, separates and the third stage’s RD-0110 engine ignites to continue the flight.
T+0:08:49: Soyuz/Fregat Separation
The Soyuz rocket’s third stage releases the Fregat-M upper stage just shy of orbital velocity.
T+0:09:49: First Fregat Ignition
The hydrazine-fueled Fregat upper stage ignites to place the SES 15 satellite into a preliminary elliptical transfer orbit.
T+0:23:34: First Fregat Shutdown
After a 13-minute, 45-second burn, the Fregat upper stage shuts down to begin a 4-hour, 34-minute coast phase.
T+4:57:35: Second Fregat Ignition
The Fregat main engine ignites again for a 52-second burn to put the SES 15 satellite into the correct deployment orbit.
T+4:58:27: Second Fregat Shutdown
The Fregat main engine shuts down after reaching a sub-geostationary transfer orbit with a low point of 1,367 miles (2,200 kilometers, a high point of 19,449 miles (31,300 kilometers) and an inclination of 6 degrees.
T+5:18:28: SES 15 Separation
The SES 15 communications satellite deploys from the Fregat upper stage.
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from Spaceflight Now